Nuclear fusion research aids EUV source breakthrough

LONDON – A University of Washington laboratory that has been working for more than a decade on nuclear fusion as a source of energy, thinks it has leapfrogged ahead of companies trying to create a viable light source for extreme ultraviolet lithography (EUV).

Zplasma Inc. (Seattle, Wash.) will be competing with such firms as Cymer Inc., Xtreme Technologies GmbH and Gigaophoton Inc. but reckons that with a 1,000 times improvement in output energy it can easily provide the source power to make EUV lithography machine throughputs viable.

The principle methods used currently are discharged-produced or laser produced plasmas of xenon or tin (DPP or LPP) but both consume large amounts of energy. More importantly neither has reached the 100- or 200-watts power level at the intermediate focus needed to get 60 to 125 wafers per hour throughput from a EUV lithography machine, such as the NXE:3300B from ASML Holding NV (Veldhoven, The Netherlands).

"We're able to produce that light with enough power that it can be used to manufacture microchips," said Uri Shumlak, a UoW professor of aeronautics and astronautics, in a report on the University of Washington website.

Click on image to enlarge.

The University of Washington nuclear fusion lab includes a tank containing plasma for energy research as well as a smaller system for electronics applications. Source: University of Washington

As with other 13.5-nm wavelength light sources, the UoW beam is based on a plasma (xenon). And the UoW fusion lab's specialty is lower-cost versions of a fusion reactor, which uses electric current rather than magnets to contain the plasma and which produces plasma that is stable and long-lived.

This has advantages over a discharge spark propagated through a tin vapor or shooting a laser at a tin droplet, the group claims. "It's a completely different way to make the plasma that gives you much more control," said Brian Nelson, a UW research associate professor of electrical engineering, in the website report.

The alternative EUV light sources produce a pulse of light that lasts between 20 and 50 microseconds The Zplasma light source lasts about 1,000 times longer and this results in more light output, and more light onto the wafer. The UoW team has been supported with grants and gifts to allow them to verify the production of 13.5-nm wavelength light and to reduce the size of the equipment.

The company is now led by Henry Berg, a technology entrepreneur, as CEO. The company is now seeking venture capital from corporate investors who can help Zplasma integrate its light sources with existing industrial processes.

For years we've been hearing that EUV will be ready for production use in "just a few more years" and now they're applying nuclear fusion technologies to create the light source? That's almost comical.

A few clarifications:
* Zplasma's design goal is higher power, not higher energy.
* Our core technology is a flow-stabilized Z-pinch. While developed as part of nuclear fusion research, it is not related to nuclear fusion itself.
* Our DPP source does use a plasma Z-pinch, but a flow-stabilized pinch, not the unstable pinch used by others in the past.
* Our source ends without the explosive instabilities of other DPP sources, so it does not produce high-energy debris.
* Optical collection in our design is side-on, not downstream.
Thanks,
Henry Berg,
CEO, Zplasma, Inc.

Another example of a misguided group/startup. They focus so much on solving a big issue, but neglect to follow up on downstream system consequences. A longer pulse per cycle obviously exposes the downstream mirrors to more ionic bombardment, despite best mitigation efforts. They need to make a positive announcement before actual integration with collection optics. Obviously, they won't get anywhere with it.

In fact, the group uses a Z-pinch plasma, same as Ushio's DPP. They have to use xenon or tin, not hydrogen (deuterium/tritium) as the plasma medium.
http://www.aa.washington.edu/research/ZaP/index.html

It is very impressive these advancements that we are currently having in the area of nuclear fusion research, hopefully soon everything will become reality in order to make a better world.
http://www.youtube.com/watch?v=ro5-QYqqxzM